Combination latch and dead bolt lock



June 24, 1969 L. B. COTHRON 3,451,704

COMBINATION LATCH AND DEAD BOLT LOCK Filed Jan. 31. 1967 Sheet I of 2Lill 38 64 INVENTOR. 72 v 3 LAWSON B. COTHRON 60 Fig. 3

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June 24, 1969 1 BJCOTHRON 3,451,704

COMBINATION LATCH AND DEAD BOLT LOCK I Filed Jan. 51, 1967 Sheet 2/ of 2X so 4 a4 8 as 82 6 as J [l' 54 9 00 so 7 o4 94 7 38 A 8% I06 54 7 "*II08 I g 94 s 'l02 e 60 92 'L ,J'? Fig.7 73 l 92 INVENTOR.

LAWSON B. COTHRON BY 6 143mm: & 14mm United States Patent 3,451,704COMBINATION LATCH AND DEAD BOLT LOCK Lawson B. Cothron, 4886 Jewel, SanDiego, Calif. 92109 Filed Jan. 31, 1967, Ser. No. 612,919 Int. Cl. Ec3/06; E05b 65/06 US. Cl. 292198 4 Claims ABSTRACT OF THE DISCLOSURE Thelock utilizes a pair of orthogonally inter-fitting elements, each ofwhich is slotted at one position to allow the other to move, one elementcomprising an indexed latch operated by movement of the door and theother being a dead bolt type locking element.

Background of the invention The present invention relates to locks,primarily for doors, and specifically to a combination latch and deadbolt lock. Existing dead bolt locks are generally of two basic types.One type uses a latch for normal operation with a separate dead bolt forsecurity. The other type uses a single bolt with latch action and somecomplex arrangement of pawls, cams, springs and the like to secure thelatch as a dead bolt.

Summary of the invention Brief description of the drawings FIGURE 1 is atop plan view of the lock assembly, with the top portion of the lockcasing cut away to reveal the mechanism in locked position;

FIGURE 2 is a sectional view taken on line 2-2 of FIGURE 1;

FIGURE 3 is an end elevation view as taken from the right hand side ofFIGURE 2;

FIGURE 4 is a view similar to FIGURE 1, with the mechanism unlocked;

FIGURE 5 is a sectional view taken on line 5-5 of FIGURE 4;

FIGURE 6 is a vie-w similar to a portion of FIGURE 1, showing adaptationto a sliding door; and

FIGURE 7 is a sectional view taken on line 7-7 of FIGURE 6.

Similar characters of reference indicate similar or identical elementsand portions throughout the specification and throughout the views ofthe drawings.

Description of the preferred embodiments The lock 10 is shown in FIGURE1 as being installed in a door jamb or wall, indicated in broken line at12, but could be installed in a door of suitable thickness, the locationdepending on the size of the lock and the operating requirements. Lock10 is contained in a frame, illustrated as a generally rectangularbox-like casing 12, having protective walls including side walls 14 and16, a top wall 18 and a bottom wall 20. At the exposed end the end wall22 has a set back jamb wall 24 which forms a stop shoulder 26, againstwhich the swinging door 28 closes. On the edge of door 28 is a striker30 illustrated here as a simple striker plate, with an opening 32,behind which is a cavity 34.

Inside casing 12 is a horizontally disposed latch element 36,illustrated as a disc, but which may be of other configurations to suitparticular purposes. Latch element 36 is rotatable about a vertical post38 fixed between top and bottom walls 18 and 20 and projects through aslot 40 in the jamb wall 24 which continues into stop shoulder 26. Inthe periphery of latch element 36 is a latching notch 42 in which thedoor is held. The small portion of the door 28, between cavity 34 andthe face of the door which confronts stop shoulder 26, forms a latchingbar 44 which fits into notch 42 when the door is against the stopshoulder. When door 28 is opened the motion of the striker issubstantially tangential to the rotation of the latch element 36, so thelatching bar 44 engages one side 46 of notch 42 and rotates the latchelement until the door is released, as indicated by the solid linearrows in FIG- URE 4. Side 46 thus constitutes the opening face, theother side of the notch 42 being the closing face 48, which latching bar44 engages when the door is closed and rotates the latching element tothe latched position, as indicated by the broken line arrows in FIGURE4. The edge portion of latch element 36 projecting into cavity 34 thusacts as a door retaining tongue 49.

Latching disc 36 is thus actuated by the door itself and holds the doorin the closed position. To keep the door in place and to maintainalignment of latching notch 42 for re-engagement by the door in theunlatched position, latching element 36 is provided with a pair ofappropriately spaced sockets 50 and 52, which are engaged by a detent54. As illustrated, the sockets are in the periphery of the latchingelement 36 and the detent is a. simple ball element 56 biased by aspring 58, but other arrangements may be equally suitable.

Deadbolt locking action is provided by a locking element 60, also shownas a disc for simplicity, which is rotatably mounted on a horizontalpost 62 between side Walls 14 and 16, substantially in the plane oflatch element 36. The latch element has a locking notch 64 in itsperiphery, through which the locking element 60 passes, the two elementsthus interfitting orthogonally, as in FIGURE 1. In this position thelatch element 36 is securely held against rotation, the locking element60 acting as a dead bolt. In the edge of locking element '60 is aclearance notch 66 through which the latch element 36 can pass, when thelocking element is rotated to the correct position. To ensure properalignment the locking element 60 has a pair of appropriately spacedsockets 68 and 70 for engagement by a detent 72, which may be similar todetent 54. In the unlocked position of locking element 60, latch element36 is free to turn, through clearance notch 66, with its open and shutlatching action.

Locking element 60 can be operated by a variety of means, such as a knobor handle coupled directly thereto, a slide bar type of mechanism, orlocks of different types. The arrangement shown utilizes the high degreeof security offered by the mechanism and includes a pair of barrel typelocks 74 and 76, one on each side, for operation of the lock from eitherside of the door. It will be obvious that a single lock will sufi'ice ifthe door is required to be locked from one side only. Each lock isoperated by a key and has an extended shaft 78 which is rotated by thekey, the end of the shaft carrying a radially extending dog 80. Locks.74 and 76 are mounted in side walls 14 and 16, respectively, with theirshafts 78 coaxial and substantially parallel to post 62. Dogs: 80project into an actuating slot 82 in the edge of locking element 60 inthe manner of intermeshing gears, so that operation of either lock willrotate the locking element to the limits imposed by detent 72. The fullline positions of dogs 80 in FIGURES 2 and show the actual engagementwith the locking elements when being turned by key. In the lockedposition of each lock with the key removed, the dog would be turnedupwardly clear of the locking element, so that either lock could be usedwithout interference by the other. To provide ample clearance, actuatingslot 82 may be fitted with laterally extending plates 84 for engagementby One dog 80. This will avoid the necessity for undue thickness of thelocking element.

It should be noted that the detent 72 can easily be made firm enough toprevent operation by the usual delicate lock picking tools. Thus withoutthe proper key, the door could not be opened except by destruction ofthe lock or the door.

With very little modification the lock is adaptable to a sliding door,as in FIGURES 6 and 7. The locking element and its actuating means areunchanged and the only alteration to the latch element is in theconfiguration of the latching notch. Since the sliding door 86 does notrequire a stop shoulder, the casing 88 has a flat end wall 90 with aslot 92, in which a portion of the edge of modified latch element 94 isexposed. Latching notch 96 is elongated and disposed at an angle to theradius from post 38, the door 86 having a striker 98 projecting from theedge to fit into the notch. Striker 98 is in the form of a U-shaped loopwith an opening 100 into which the latch element 94 enters, and alatching bar 102 which is actually held in the latching notch. Theinside face of latching notch 96, or the face nearest post 38, comprisesthe closing face 104 and the outside face of the notch becomes theopening face 106, comparable to the arrangement of latching notch 42.

When latching bar 102 engages the closing face 104 as the door is closedin a direction generally radial to the latch element, the inclined faceacts as a ramp and the pressure causes rotation of latch element 94. Thetongue portion 108 of the latch element, outside notch 96, enters thestriker opening 100 and the latching bar 102 is seated at the closed endof the notch. When the door is pulled open, the latching bar bearsagainst the inclined opening face 106 and rotates the latch element inthe opposite direction until the striker is released. The closedposition is indicated in full line and the open position in broken linein FIGURE 6. The latch element 94 is actuated entirely by opening andclosing the sliding door, just as latch element 36 is operated by theswinging door. With looking element 60 in locked position, as in FIGURE7, latch element 94 is held securely against rotation and striker 98 istrapped in latching notch 96 with complete security. A channel toreceive the door edge, or weatherproofing seals may be added in theusual manner and would serve to conceal the small gap between the doorand jamb, so preventing cutting of the striker, which is the only methodof forcing entry without considerable destruction.

Apart from the actuating means for the locking element, which can vary,the actual lock mechanism utilizes only two moving parts, the latchelement and the locking element. Yet this simple arrangement providesall the con venience of a door actuated retaining latch and release andthe security of a dead bolt. The two elements can be made very rugged toresist damage, as opposed to the delicate cams, springs and the like inother locks of comparable type.

It is understood that minor variation from the form of the inventiondisclosed herein may be made without departure from the spirit and scopeof the invention, and that the specification and drawings are to beconsidered as merely illustrative rather than limiting.

It is claimed:

1. A combination latch and dead bolt lock assembly, comprising:

a lock unit for attachment to one portion of a structure and a strikerfor attachment to another portion of a structure to be locked to thefirst portion;

said lock unit having a frame;

a disc latch element mounted in said frame for rotation about an axissubstantially perpendicular to the direction of motion of the strikerrelative to and adjacent to the lock unit;

an edge portion of said latch element having a latching notch therein toreceive and retain a portion of said striker, said latching notch beingdisposed at an angle to the corresponding radius of the disc latchelement and defining a tongue portion between the latching notch and theadjacent edge portion of the latching element to engage said striker inthe locked position;

a disc locking element rotatably mounted in said frame and having aportion engageable with said latch element to lock the latter againstrotation;

and means to move said locking element selectively into and out ofengagement with said latch element.

2. The structure according to claim 1, wherein said locking element ismounted for rotation about an axis substantially perpendicular to theaxis of said latch element and overlaps the latch element in orthogonalinter-fitting relation therewith;

said locking element having a clearance notch through which said latchelement can pass in an unlocked position;

and said latch element having a locking notch into which said lockingelement fits in a locked position.

3. The structure according to claim 1, wherein the direction of motionof said striker relative to said latch element is substantially radialto the axis of rotation thereof;

said latching notch being inclined to the radius and the faces of saidlatching notch being ramps engageable by said latching bar to rotate thelatching element when unlocked and retaining the functionality of saidtongue portion to engage said striker when in locked position.

4. The structure according to claim 1, wherein said frame has protectiveside walls and an end wall having an opening in which is exposed aportion of said latch element having said latching notch therein forengagement with said striker, said end wall at one side of said openingtherein having a stop shoulder against which said another portion of thestructure abuts when in locked position.

References Cited UNITED STATES PATENTS 1,462,684 7/1923 Clum 200442,217,098 10/1940 Brownne 2922l0 2,910,859 11/1959 Allen 135 MARVIN A.CHAMPION, Primary Examiner.

E. J. MCCARTHY, Assistant Examiner.

US. Cl. X.R. 70135

